Atomic

iTrader: (42)

These are from my 5.3 with tvs1900



Discoloration from too much timing or what?

offroadrider12

That one on the bottom left doesn't look so good.

mhotrodscooter

iTrader: (13)

Have to get closer pics! Looks like right burning better the left from pics

budhayes3

iTrader: (19)

The ones on the left are in the shadows, but the ones on the right look perfect, a tannish color is good and the sign of a complete burn

fastnblu

iTrader: (2)

I'm w/.BH3 on all counts; tan is good. Plug on LL may be an isssue tho.

Atomic

iTrader: (42)

Oh ok, sweet. The ones I pulled form my 408 still look brand new, as expected.

MikeGyver

iTrader: (5)

The only thing you can tell by looking at the tips of the insulators is if the heat range is OK.
You need lights and magnification to look down where the insulator meets the metal body of the plug to check AFR.



Read this and raise your level of consciousness:
http://www.strappe.com/plugs.html

budhayes3

iTrader: (19)

The blackened plugs that I've pulled out of numerous vehicles with faulty fuel regulators, bad O2 sensors, incorrect ignition timing, etc. would have to say different...I learned this about 25 years ago when I had a runability problem with my 67 Nova that had the carburetor misadjusted and it was running too rich...

MikeGyver

iTrader: (5)

Your example is the exact answer I expected, but didn't include because it is at the extreme. Of course super rich or super lean will show up on the tip of the insulator, but at that point you are diagnosing faults, not tuning for power. Prior to wide band oxygen sensors, if you were tuning for power, you knew how to read plugs as in the article at the bottom of my first post. There is a lot of information about your tune available, if you know what to look at.

budhayes3

iTrader: (19)

Well obviously a spark plug is not a direct indication of afr, and with the tools and software available to us today, there's really no need, but, if you've been doing it for years, and know what to look for, a spark plug can be a useful diagnostic tool. I'm pretty sure that the OP has tuning software from what I remember, and was looking for an answer as he's not used to reading spark plugs on a daily basis as someone who has been turning wrenches and tuning automobiles for a living their whole life might. I'm guessing that he saw the tannish color and took it as an indication of a problem, and was relieved to hear that what he saw was totally normal. Also, it's been my experience that an engine doesn't need to be super rich to leave carbon behind...rich enough to notice negative fuel trims, but not rich enough to trip a P0172 or 175.

Now trying to read in iridium plug is a completely different story...